A system and method for preparing high-purity vanadium pentoxide powder by an efficient and clean chlorination method

Abstract

The invention belongs to the fields of metallurgy and chemical industry, and specifically discloses a system and a method for preparing high-purity vanadium pentoxide powder through an efficient cleanchlorination method, wherein industrial-grade vanadium oxide is converted into vanadium oxytrichloride by combing fluidization and carbon chlorination, two-stage dust removal and four-stage leachingare performed to obtain crude vanadium oxytrichloride, and the crude vanadium oxytrichloride is subjected to purification, catalytic oxidation and calcination to obtain the high-purity vanadium pentoxide powder. According to the present invention, the too high furnace temperature is prevented by spraying the vanadium oxytrichloride slurry into the boiling chlorination furnace; the chlorine gas isregenerated by blowing clean oxygen-rich air into the catalytic oxidation fluidized bed; the hydrogen chloride is recycled by returning the hydrochloric acid to the catalytic oxidation fluidized bed;and the system and the method have advantages of strong raw material adaptability, self-circulation of chlorine gas, no vanadium-containing hydrochloric acid emission, low production energy consumption, low operation cost, stable product quality and the like, are suitable for the large-scale industrial production of high-purity vanadium pentoxide powder with the purity of more than 4N, and have good economic and social benefits.

Description

technical field [0001] The invention belongs to the fields of metallurgy and chemical industry, and in particular relates to a system and method for preparing high-purity vanadium pentoxide powder by an efficient and clean chlorination method. Background technique [0002] With the continuous development of new energy technologies, the demand for high-purity vanadium pentoxide (purity above 3N5) is increasingly strong in the battery industry, including all-vanadium redox flow batteries (VRB) with good large-scale energy storage performance and vanadium for electric vehicles Acid-based lithium-ion batteries, etc. [0003] At present, the process technology for preparing high-purity vanadium pentoxide can be roughly divided into two categories: wet purification process and chlorination purification process. The main process route of wet purification is: vanadium solution purification - ammonium salt precipitation - calcination - vanadium pentoxide. In the above-mentioned wet...

AI Technical Summary

Problems solved by technology

This patent has the following deficiencies: (1) carbon chlorination is a violent exothermic process, which needs to transfer heat to the outside of the chlorination furnace; air is blown into the chlorination furnace in this patent, which will cause the furnace temperature to rise and affect Fluidized state; (2) The flue gas dedusting-condensation part is very simple, and the chlorinated flue gas is mixed with a large amount of unreacted dust. A single cyclone separator cannot achieve effective dust removal effect, and the backward movement of dust will block the follow-up pipe Road, bring the hidden danger of stopping production; Simultaneously insufficient vanadium oxychloride condensation will reduce recovery rate greatly, increase production cost; (3) rectifying purification can only separate the metal chloride that differs greatly from the saturated vapor pressure of vanadyl trichloride However, some such as titanium, silicon chloride and vanadyl chloride saturated vapor pressure are close, and it is difficult to obtain high-purity vanadyl chloride by the method of rectification alone; (4) gas phase ammonization-ammonium salt calcination process will produce a large amount of chlorine Ammonium chloride and ammonia-rich tail gas increase environmental protection costs

This patent has the following deficiencies: (1) There are a large amount of impurities such as iron, manganese, chromium, titanium, and aluminum in the vanadium slag, which are converted into chlorides in a large amount during the chlorination process, and a large amount of chlorination tailings pollute the environment and cannot be used economically and efficiently; (2) This patented technology also has the problems of overheating of the chlorination furnace, blockage of pipelines, low recovery rate of vanadyl trichloride, substandard purity of vanadyl trichloride, and inability to handle a large amount of vanadium-containing hydrochloric acid

The technologies disclosed in these patents are similar to the aforementioned patents, and there are mainly problems of ammonia nitrogen wastewater and vanadium-containing hydrochloric acid

[0006] In addition, for large-scale industrial applications, the existing industrial-grade vanadium oxide chlorination technology still has the following four problems: (1) The chlorination of vanadium oxide is a strong exothermic process, and the heat generated by the chlorination reaction can satisfy In addition to the preheating of solid and gaseous reaction materials, there is still a large amount of surplus, which will lead to local overheating of the vanadium material, affecting the fluidization state and the selectivity of chlorination. It is necessary to find an effective way to remove the heat from the fluidized bed; (2) chlorination fume The dedusting and condensing section of the gas is related to the continuity of production and the recovery rate of vanadium trichloride, which requires special devices to be strengthened; (3) rectification / distillation purification can only separate the gas with a large difference in saturated vapor pressure from vanadyl trichloride Metal chlorides, yet some such as titanium, silicon chloride and vanadyl trichloride saturated vapor pressure are close, it is difficult to obtain high-purity vanadyl trichloride by the method of rectification / distillation alone, need to coordinate other effective impurity removal methods; (4 ) preparing vanadium pentoxide by vanadium oxychloride still does not have a clean, efficient and environmentally friendly preparation method

If the chlorine gas cannot be recycled and the vanadium-containing hydrochloric acid cannot be effectively treated, the production cost and environmental protection cost will be greatly increased, and it will be difficult to realize large-scale industrialization

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